[chore] add remove-toolchain make cmd (open-telemetry#35490)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->

This PR adds a new `remove-toolchain` make command which removes the
`toolchain` directive from all go.mod files.
The new make command is also added to the `update-otel` make target.

**Link to tracking Issue:** <Issue number if applicable>
- fixes
open-telemetry#33600
- could potentially also work for
open-telemetry#35160

**Testing:** <Describe what testing was performed and which tests were
added.>
- add a `toolchain go1.22.5` directive to any of the go.mod files in
this repo
- call `make remove-toolchain`
- check if the toolchain directive was removed

---------

Signed-off-by: Moritz Wiesinger <[email protected]>

Author: mowies

Makefile

@@ -118,6 +118,10 @@ gogci:
 gotidy:
 	$(MAKE) $(FOR_GROUP_TARGET) TARGET="tidy"
 
+.PHONY: remove-toolchain
+remove-toolchain:
+	$(MAKE) $(FOR_GROUP_TARGET) TARGET="toolchain"
+
 .PHONY: gomoddownload
 gomoddownload:
 	$(MAKE) $(FOR_GROUP_TARGET) TARGET="moddownload"
@@ -404,11 +408,12 @@ update-otel:$(MULTIMOD)
 	$(MULTIMOD) sync -s=true -o ../opentelemetry-collector -m beta --commit-hash $(OTEL_VERSION)
 	git add . && git commit -s -m "[chore] multimod update beta modules" ; \
 	$(MAKE) gotidy
-	$(call updatehelper,$(CORE_VERSIONS),$(GOMOD),./cmd/otelcontribcol/builder-config.yaml) 
+	$(call updatehelper,$(CORE_VERSIONS),$(GOMOD),./cmd/otelcontribcol/builder-config.yaml)
 	$(call updatehelper,$(CORE_VERSIONS),$(GOMOD),./cmd/oteltestbedcol/builder-config.yaml)
 	$(MAKE) genotelcontribcol
 	$(MAKE) genoteltestbedcol
 	$(MAKE) oteltestbedcol
+	$(MAKE) remove-toolchain
 
 .PHONY: otel-from-tree
 otel-from-tree:

Makefile.Common

@@ -211,6 +211,10 @@ tidy:
 	rm -fr go.sum
 	$(GOCMD) mod tidy -compat=1.22.0
 
+.PHONY: toolchain
+toolchain:
+	$(GOCMD) get toolchain@none
+
 .PHONY: misspell
 misspell: $(TOOLS_BIN_DIR)/misspell
 	@echo "running $(MISSPELL)"

exporter/dorisexporter/go.mod

@@ -2,8 +2,6 @@ module github.com/open-telemetry/opentelemetry-collector-contrib/exporter/dorise
 
 go 1.22.0
 
-toolchain go1.22.7
-
 require (
 	github.com/cenkalti/backoff/v4 v4.3.0
 	// cannot use higher version: https://github.com/go-sql-driver/mysql/issues/1602